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Subject: RE: [chromapolaris] Column of membrane buttons not working

From: "Paul D. DeRocco" <pderocco@...>
Date: 2015-02-03

> From: rob.ocelot@...
>
> At the moment I'm testing the Frankenstein's membrane panel
> and the panel boards in the Good Polaris. So far almost every
> function works except for the sweep rate slider (probably
> dead) and the far right column of membrane buttons and LED's
> do not function, along with the Detune button.
>
> Anybody know which panel matrix trace corresponds to these buttons?

The service manual is here:

http://www.rhodeschroma.com/?id=polarisservicemanual

The line common to those switches is the SW7 line, which is on connector
J9B pin 9 on the right board. First, make sure the tail is properly
aligned with the connector pins. Then, you might also look inside the
connector with a magnifier to see if there's any crud from the old tails
clogging it up. It's hard to imagine a failure in one of the electronic
parts causing the problem, because the only parts that are involved are
R16, a 1/4W resistor, and one section of Z3, an LS-TTL chip.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...